Biomedical subjects

M Hallman

Publications and source records attributed to M Hallman.

202 records · Page 12Linked to original sources

PubMedDate not supplied

Immediate effects on lung function of instilled human surfactant in mechanically ventilated newborn infants with IRDS.

We have studied the effects on lung volume, respiratory mechanics and ventilation during the first hours after instillation of 60 mg/kg of human surfactant into the trachea of 4 very preterm, newborn infants with severe IRDS under mechanical ventilation. Measurements were made with a "face-out" body plethysmograph and a modified nitrogen wash-out method. In addition to a transient decrease in total and alveolar ventilation immediately after the instillation we found an immediate rise in lung volume, but respiratory compliance decreased. These changes lasted less than two hours. Oxygen requirements fell in 3 out of 4 infants. The changes in lung volume and compliance are explained in terms of changes in the shape of the static recoil pressure characteristics of the diseased lungs after treatment. Mechanisms behind the short duration are sought in mode of instillation, dosage, age at treatment, and severity of disease.

Humans↗

PubMedDate not supplied

A prospective randomized study of 1- and 2-stage sinus inlay bone grafts: 1-year follow-up.

The purpose of the present study was to compare the success of and surgical differences between 1- and 2-stage sinus inlay bone grafts and implants after 1 year in function. The individual risk for implant failure in grafted areas among 1-stage patients was about twice the risk in 2-stage patients (odds ratio 2.3, CI 0.6; 8.5). The risk for implant failure in non-grafted areas was significantly lower (P < .05) than in grafted areas, regardless of the technique used. Forty edentulous patients, selected according to strict inclusion criteria from consecutive referrals, were allocated to one or other of the 2 sinus-inlay procedures. Twenty patients received bone blocks fixed by implants to the residual alveolar crest in a 1-stage procedure (group 1). In another 20 patients, particulated bone was condensed against the antral floor and left to heal for 6 months before implants were placed (group 2). An almost equal number of implants was placed in the patients of each group, 76 in the 1-stage procedure and 74 in the 2-stage procedure. Additionally, 72 and 66 implants were placed in the anterior non-grafted regions of group 1 and group 2 patients, respectively. After 1 year in function, a total of 20 implants failed in 1-stage patients, versus 11 in 2-stage patients. Sixteen and 8 implants, respectively, of these were placed in grafted bone. All but one 1-stage patient received the planned fixed prosthetic restorations, but 1 restoration was redesigned after the first year in function because of a functionally unacceptable prosthetic design. At the 1-year follow-up, one 2-stage patient lost her prosthesis as the result of multiple implant failures. Bruxism and postoperative infections were the only parameters that could be related to implant failure, however, depending on the statistical method used.

Adult↗

PubMedDate not supplied

A prospective study of treatment of severely resorbed maxillae with narrow nonsubmerged implants: results after 1 year of loading.

The aim of the present study was to evaluate the use of reduced-diameter implants as an alternative to bone grafting for treatment of patients with severely resorbed maxillae. Forty patients (25 females, 15 males, mean age of 57 years, range 19 to 86) with insufficient bone volume for placement of standard-size implants in the maxilla (31 totally edentulous) were treated with 3.3-mm-diameter implants (ITI, titanium plasma-sprayed solid screws). Augmentation was considered for all patients because of lack of sufficient bone volume. Preoperative radiographic examination showed that in all cases, the height of the alveolar crest with a width of 4 mm was less than 10 mm. A total of 182 implants with a length of 8 to 12 mm were placed. All but 3 patients planned for overdenture treatment received fixed prostheses or single crowns (n = 3). One implant (8 mm long) was lost 1 month after placement, providing a survival rate of 99.4% after 1 year of loading. Since 4 implants with peri-implantitis were successfully treated and 1 implant left as a "sleeper" because of malposition, the cumulative success rate was 96.4%. The mean marginal bone resorption at baseline was 0.14 +/- 0.67 mm (range 0 to 6 mm). After 1 year of loading the mean resorption was 0.35 +/- 1.05 mm (range 0 to 7 mm); 4.8% of the implants had marginal bone resorption of more than 2 mm.

Adult↗

PubMedDate not supplied

Pulmonary mechanics generated by positive end-expiratory and continuous negative pressure.

Pulmonary function measurements were studied on equivalent levels of positive end-expiratory pressure (PEEP) and continuous negative pressure (CNP) while controlling for transpulmonary pressure (TPP). Four adult rabbits were anesthetized, instrumented, and ventilated with intermittent mandatory ventilation by using peak inspiratory pressure (PIP) of 16 cm H2O, PEEP 0 cm H2O, CNP 0 cm H2O, inspiratory time 0.3 seconds, rate 20/min, and fraction of inspired oxygen of 0.3. Subsequently, equal amounts of PEEP and CNP were alternated for 15-minute ventilation periods. PIP was changed to approximate the TPP in each PEEP/CNP pair. There was a significant decrease in PCO2 and increase in pH, mechanical tidal volume, minute ventilation, functional residual capacity, and total dynamic compliance on CNP. These differences could not be explained by changes in TPP.

Animals↗